Hello Karan Vanni
yes for sure you can use Digi locker for uploading documents for Appling NIOS or any other exam form because its 100% safe and Secure.
DigiLocker is India's own cloud storage service for government-issued documents. DigiLocker is a cloud storage service for your government-issued documents created by Ministry of Electronics & IT (MeitY) under Digital India Corporation (DIC)
Thanks
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile